Electric-current-controlling apparatus.



A. E. BERDON. ELECTRIC CURRENT GONTROLLING APPARATUS.

l APPLICATION FILED KAY 10, 1913. 1,108,320. Patented Aug. 25, 1.9M

l cation Serial No. 7 66,873, V,filed ,ofeven normal direction. to havethe current reversed 1n order to open 7 UNITED sTATEs PATENT orifice; l

ALBERT E. BERDON, 0F INDIANAPOLIS, INDIANA.

y ELncTRrc-CURRENT-CONTROLLINGAPPARATUS.

Specification of Letters-Patent.

Patented Aug. 25, 1914.

Application flied May 1o, i913. serial No. 766,574.

Tof/lll 'whom it may concern Be it known that I, ALBERT E. BEnDoN,citizen of the United States, residing` at Indianapolis, in the countyof Marion and State of Indiana, have invented a certain new and usefulImprovement in Electric- Current-Controlling Apparatus, of whichmaintained closed as long as any current is flowing in the-positive ornormal-direction, opening of the working circuit be1n0 permitted at atime when thecurrent is o zero value 'or is very slightly reversed. If

desired, the working circuit may be also `opened when the'currentreaches a predetenmined minimum value in the positive or It need notbe'essential the main working circuit switch contacts, though it is tobe understood thatthe apparatus is to be, adjusted to have thesecontacts open when the current reaches any p1 edetermined value in thenormal or positive and reverse directions. The apparatusv may beadjusted' to open the main orworking circuit quickly and positively,when such opening is. to ,be occasioned-by reyerse cury rent, bypermitting such reversedcurrentto reduce the effective magnetism 1n themagnetic circuit of the circuit controlling, mag.-w

net. The magnet which emply'is .desirably that disclosed in myt(x0-pending appliate herewith. 4 y I will explain my invent-ion. morefully by reference to the accompanying drawing showing the preferred4embodimentthereof and in which- .Ffgure l isa ,diagrammatic-viewillustrating theinvention; Fig. Q.isv a plan-view of some of thestructural partsillust'ra'ted in Fig. l; and 3 and 4 ,are diagramsillustrating the magnetic ux. v I

Like parts areiindic'ated by similar charyactersof reference throughoutthe diiierent figures.

Referring first particularly' to Figs.- 3 'and i '4, I will firstdescribe the magnetl which ment. This`magnet ypreferably includes noipermanent magnet in its formation, the lwinding core l being preferablyof soft unlaminated iron having soft iron polar eX- tensions 2 and 3secured toits ends by means of screws 4, these'soft iron polarextensions extending laterally of the core fora suicient distance uponeach side of the core to' ,i alford properlimits to the magnet windingspace and each being inturned in 'approaching directions upon oneside ofthe coreas indicated at 5, va suitable gap intervening between theinturned polar extension ends there to constitute a gap in the magneticcircuit. lvThis gap is bridged by a soft iron armature G whose lowerface is formed-with a rounded fulcrumridge 7 affording a'rolling contactbetween the armature and one of thepolar extensions 3 upon which thearmature is supported adjacent the ap between the polar extensions.v Theulcru'm ridge `7 is located substantially midway be-Y tween the ends ofythe armature 6 whereby the armaturev is caused preferably to overliesubstantially all of the insetting extension of the polar extension 3upon which the armature is mounted, the otherend of vpreferablyconstitutes', a part of the equpss.l

the armaturejoverlying a sufiicientportion of the insetting extensionofthe other polar extension 2 to enable theproper passage ofthe-,magnetic flux. In the absence 4ofpsuiiicient tracti've `effortlbetween the polar extension .Q and `the armature 6, a spring v8operates tfo'idrawthe right-hand end of .the

armature" v'downwlardly until the non-niag-':

netic stopj9 engages the vpolar'.'c axten'sic'nn 3'. VheIi''the'.magnetic `attraction 1s suicient,

'move the armature'in 'a 'counterclockwise direction, the'extent' offmovement thls direction benglimited byla stopl() ofY non- Alm lgneticmaterial "adapted for ,engagement zwith the polar extensionQ. The forcef 'the springis regulated' by"A a ,horizontallyE h djustable 'screw' 111workin upon the ad]a cent and inclined end of the'sprin-g l'8. g espring operates upon the armaturethrugh the intermediation of thestrutzlj'fsv'vingjingly connected at its upper end "with the armatureand at its. lower end with a spring tongue 13 projecting upwardly fromand being integrally formed with the spring.8.

The flux set up within the magnetic cir-r cuit established by theelements 1, 2, 3, 6 and 7 is diagrammatically indicated in Figs. and aby the flux lines having the arrow heads Ipointing ai direction of flux.'llhc fulcrum ridge 7 is integrally formed with the 9 armature 6 and-hasmagnetic contact with .the pelar extension 3, the lines of force hav-"ing one ilis'ti'iln1tion 'at the armature when Y the armature istunattracted and another distribution when thearmature is attracted, i5the-'portions'of lthe lower armature acebei ing desi'rlablyangularlyyrelated to permit .nture continues to move in responsetoits :o magneticattraction whereby the magnetic reluctance at its right hand air gap in'creases and progressively increases toward the right hand limit of thearmature so as to effect a progressively increasing concentration of thelinesfottorce toward and. at the fulcrum ridge thereby progressively/.toreduce the magnetic Apull upon the right hand endof the armature as tfhearmature is moving to itsvmagnetically attracted pofn '0 'sition wherebythe flux across the air gap fat thejleft hand'end .of the armature, asit is 'progressively shortened,- may cause the more rapidpositive'f-'closing movement of z the armature, the :magnetic oppositionto such closing movementfat the right hand end `or the armature' beingrariidly-and..A progressively decreased as will be understood forreasons above explained and owing also to thelengthening of theportionsoi" the-lines of force that span theprogressively increasing airgap at the right hand end of the armature.. Thus all.the lux traversesthe gap at the left handA end of-the armature while .the portion which.traverses the gap at the right hand Vend of the armature provgressively decreases as this latter gap is widened, a result which isrendered possible `[owing to the'reduction of magneticreluctanceat 7where a path lis aorded for increasing flux diverted therethrough owingto the increasing reluctance at the rightfof the armature. In.otherwords there is but one tluX path at the leftof the armature and`there are two nuri paths at the righthand portion of the amature, one ofthese latternioaeao twotilnx pathsincluding the ulcrum 7 and lirst'of`these two shuntrelated paths from the secend of such paths as the righthand air ga increases and more being diverted throng the second of suchpaths Vfrom the jlirst aslthis right hand air gap decreases.

The s acing intervening between the tulcrum and the lett hand air gap isselected to 'enable the flux there to eii'ect magnetic attraction asdesired, the sum of the lines of forcent the' leit hand air gapmultiplied by ntheir respective distances from the fulcrum 7 lquicklybecoming greater than a similar summation at the right hand air gap when'the armature is being magnetically attracted.` As' soon as the armaturemoves the slightest owing t'o magnetic attraction a rej'distribution ofthe flux along the lines above 4set forth is immediately commenced andrapidly continues to insure a rapid and complete closing stroke of thearmature after the initial unbalancing of the flux at 'the opposite endsof the armature occurs ythe tendency .of the armature 6 Vto continue`the entire stroke upon which it has coinrnenced being sostrong that 1twill take its full movement even though the initial magnetizingforce'required to start the movementhe largely'reduced. |lfhe stripmetal springs 17 and 18 carry disk-shaped contacts 27, 28, the stripmetal spring 25 engaging the spring 18 near the outer peripheral portionof the disk contact 28 for the purpose of `vso nexing the spring 18 asto enable the opposing'faces of the contacts 27 and 28 to :1

be in exact parallelismv'when .the contact 27 is on the point ofapplication to the contact 2Sr when the spring 17 carrying contact27 ismoved upwardly by the armature through 'the' intermediation of theinsulating post ,24, wherebv the adjacent faces of these contacts areinitially in engagement throughout to prevent undue introduction ofresistance Y at this pointvof contact. The stop 26 is adjustable to.enable the spring 18 to be properly initiallyl positioned, the stop 26operating upon the spring 18 through the spring 25. The spring 17carries a lower contact engaging a normal contact upon the spring `21.extent to which the spring 21 may be flexed upwardly due to its ownresilience when' the Spring 17 isiiaed. f

An adjustable post 23 limits the Referring nowalso to Figs. 1 and 2, asuitably driven vdirect current generator 1 4: 1-5 of low voltage, saysiX volts, is in serial relation. with the current coil l5 disposedabout the core 1 and of comparatively few turns and negligibleresistance, wound in such direction that current in the normal ordesired directidn tendstoproduce iuxin a direction corresponding totheflux lset up by the pressure Winding 16 (which is also dis-.

'posed about the. core 1 but normaliydn shunt of the elements 14 and 15)when the `forded by the elements 1,2, 3 and 6. The

voltcoil 16 is high Wound with 'reference to' the coil 15 and isdesigned to withstand' full potential of the source of current beingcontrolled Without injurious heating. The coils 15 and 16 arecumulatively Wound assuming' `the voltage to be of normal polarity, The

coil 15 is included in a circuit that contains spring 17, spring 18 anda .battery 19 Which may be a three cell, .six volt storage batteryadapted to supply a Anumber of sixI volt lamps or otliei" load 20 withcurrent when the switch 201 is closed, the generator 11 being includedin the circuit that contains said spring 18 and battery 19. Theshuntpath including the. pressure Winding 16 is multiplied from the lefthand terminal of the Winding 16, one of these multiplied paths includingthenormal follow-up spring contact 21 and the spring17 yfollowed bycontact 21 and the other includin the Windin 227 (normally shortcircuited y springs 1 and 21), the shunt connection effected for thecoil 16 With the Winding 15 by Wayoi thecoil 22 being 'permanent Whilethe shunt connection of the coil- .1 6 with the coil V15 through tliesprings 17 and 21 is adapted to be made and broken at these springs dueto the, operation of the magnet.

i ratus let it be assumed that the generator 14 In describing theoperation of the appais started from rest and' radually increases to itsmaiiimum speed. he generator voltvage rises'from Zero asthe generatorspeed 'be traced from the positive brush of the- ,generator 14 throughthe series Winding 15 increases and a circiiitis initially presenttraceable from the positive brush of the genei'atorthrough the seriescoil 15, the spring 17, the spring 21,A the high Wound voltage .'coil16, to the negative generator brush.

Another circuit is initially present and may the resistance' coil 22,the high Wound voltage coil 16, to the negative brush of the generator.In this condition of tliings'the nori'nally engaged contacts :oftlies'prings 17 and 21 short circuit*the coil 22,` t his conv-v ditionremaining until the voltage of the generator rises to a predeterminedvalue (in the example chosen say 6.8.r volts by Way vof illustration)whereupon -the magnetic flux at the left hand end of the armature 6overcomes'the flux at the right hand end of thev armature and thesupplementing pull Vof l the strut to which may be addedthat thearmature completing its full stroke even though `the force required tomove it inagi 70 rapid, for the reasonsherein pointed out,

netically be greatlyreduced. When the arff mature is magneticallymovedit first causes engagement between springs 17 and 18 and thereaftercauses the engagement" between thesprings 17 and21 to 'be broken, thecon'- tacts of these latter springs being followup'contacts?v Alteredcircuit conditions are now consequent, one circuit being traceable fromtlieqpo'sitiye brush `of the generator 14y through the series coil 15,theres'istance coil 22, Athe lvoltage. coil 16,V to the Nnegative brush.of the generator, the short circuit about the coil 22 having beenbroken owing to the separation 'of the" springs 17 and 21. The coil 22'now in shunt of the generator by Way of coil' 16 and also introducedinto circuit ywith the coil4 15, being differentially:

Wound with respectto ythe coils 15 and 16,'

reduces the magnetizing effect of the coils 1 5 and 16 upon the `core- 1so that if there be no current, or current o f minimum value ,i

in the normal direction, o'r sm'allcurent in an abnormal or negative'direction, (according' to the adjustment of the equipment) owing in thecoil 15 tl'ievsp'ring 8 Will be effective to retract the armature to itsnorinal magnetically unattracted position. In

practice this reduction'of themagnetizing` effect of the coil 16 amountsfto forty `or fifty' per cent., this reduction being largely acof coil22 and being partly accomplishedby the V reduction of theeffeotiveai'npere tiirns `on corel by virtue Aof the opposingdireccomplishedvby reducing the current" through f the coil 16 by virtueofthe ohmic resistance tions of current in the coils 42 and 16. The

function' effected by the ohrnic jresis'tanceof the vcoil 2 2 isobviously accomplished Whethenth'is coil be in or outof magnetizingrelation to tlie core 1, and this aspect ofthe invention is not tobelimited tothe Winding of the coil 22 upon the core `1. The oppos' ingLmagnetomotive force vset upby the coil 22 'is a factor which is notnecessarily dependent upon the ohmic resistance of the coil 22 'and thisaspect of the-invention is not to be limited to a high resistance forthe.

- By my equipment there are obtained oper.

iis

, no" 'coil 22 Wli'enit is in magnetizing relation' to. Athecore 1.

ating losses which are low and liih eier- 'voltage protection and alsothatwhicli is'of utmost importance, namely, the separatipn pf thesprings 17 and 18 Whentl'ie current 5 has been reduced toi zero or theminimum or say a very small'reverse Value, according to the adjustmentof the equipment, .the

leef

contacts being thus protected from arcing.

The generator is also rendered safe from having its fields reversed dueto the big reversed currents flowing in the series winding from thebattery possible in" some outfits.

lln thc magnetically y unattracted (or spring actuated) position of thearmature 3 with the voltage below 6.8,' the generator cannot send anycurrent through the working circuit although the battery can sendcurrent through such circuit if the switch 2017be closed. With thearanature in its magnetically attracted position a circuit ymay betraced from the .positive brush of the generator 14 through the seriescoil 15, the

springslY and 18 (the spring portion 25 also being 'included in thiscircuit,it being v`in parallel with the spring 18) the positive terminalof the battery 1S), the negative terminal of this battery, to thenegative brush oiE the generator. Upon increase of the generator speedbeyond the speed required to impress 6.8 volts, the voltage is kept downto that of the battery voltage plus the rey .sist-ance timescurrent (l.R. drop) of the series coil 15 and the line Wiring, the main contactsremaining closed for all positive values or all predetermined positivevalues of current.` As the speed of the generator reduces graduallycurrent through the battery reduces until the generator voltage andbattery voltage are equal, at which time no current will flow to themain circuit. If the controller is properly set by the adjustment of thescrew 11 upon the spring 8, the armature will then Yopen and return toits origil. nal position, it being assumed that the apparatus is to beadjusted thus to operate when there .is no current ilowing. In practice`it hasbeen found advantageous to enable the apparatus to operate atzero current -or at one-quarter to one-half ampere maximum vreversecurrent. lli/'hen the arlmature begins to move to its originalmagneticallyv unattracted position it quickly makes the entire stroke,contact `between the springs 17 and21 being made before contact betweenthe springs 17 andl 18 is broken. By way of example but in no wiselimiting theA scope of the invention, values and dimensions jmay beassignedl as follows: Cun.

. rent coil 15, negligible resistance., may in clude eighteen turns ofNo. 12 (Brown t Sharpe gage) copperwire. Resistance winding 22 may beofl twenty-two ohms resistance and have forty-tour turns No. 27 Idealwire. Pressure winding 16 may be of seventeen ohms having nine hundredtwenty-five turns No. 29 D. C. C. copper wire.

In the equipment illustrated it is possible to have current through thecoil 15 reverse in di- J rection while current 1n coil 16 remains 1n its8 were set so'yweak that a reduction of line direction, a result thatwould follow if spring 'incasso voltage below battery voltage would notcause contacts 27, 28 to open, reverse current consequently flowingthrough the coil .15 while the voltage impressed 'upon the coil y turnsfurnished by the coil 16 or by reduc ing the ampere turns of the coil 16owing to the ohmic resistance of the element 22, these two functionsbeing both accomplished by the saine element 22 in thepreferred'embodiment of the invention.

)While l have herein shown and particularly described the ypreferredembodiment of my invention ll do not wish to be limited 9a toA theprecise construction and circuit arrangement shown as changes mayreadily be made without departing from the spirit of my invention, but

Having thus described my invention l claim. as new and desire to secureby Letters Patent the following :--J f 1. An electric current`controlling device and an electric 'circuit controlled thereby,

which circuit has a current supplying generator, said device includingan electro-magnet having an energizing current winding receiving currentfrom the controlled circuit, an energizing pressure winding subject tothe pressure of such circuit, these two wind; 105 ings beingcumulativelywound, and a thirdL y energizing Winding of high resistancecompared with the first energizing winding and differentially wound withrespect to the aforesaid windings; and a switch having a 1l@ contactactuated bythe magnet and serially in the controlled circuit, a normalfollow-up contact engaging the first contact and by which follow-upcontact the second winding is included in shunt of the generator, and an115 alternate contact serially inthe controlled circuit and engaged bythe first contact before the rst contact leaves its normal follow-upcontact, the first two contacts having circuit association causing them,by their engagement, to shunt'the third winding from the remainingwindings and by their separation to bring the third winding in shunt ofthe generator by way of the second winding,

while the latter two contacts, by their engagement, serve to establishthe controlled v circuit. v

2. An electric `current controlling device and an electric circuitcontrolled thereby,

which circuit has a current supplying generator, said device includingan electro-magnet having an energizing current winding .receiviiigcurrent from the controlled circuit, an lenergizing pressure windingsubject to the pressure of such eircuitthese'l two windings' beingcumulatively wound, and a third the generator, and an alternate contactse` rially in the controlled circuit and engaged by the first contactbefore the first contact leaves its normal follow-up contact, the firsttwo contacts having circuit association causing them, by theirengagement, to shunt the third winding from the remaining windings andby their separation to bring the third winding in shunt of the generator'by way ofthe second winding, while the latter two contacts, by theirrengagement, serve to establish the controlled circuit. v

8. An electric current controlling device and an electric circuitcontrolled thereby, which circuit has a current supplying generator,said device including an electro-magnet having an' energizing currentwinding re-y ceiving current from the controlled circuit, and anenergizing pressure winding subject to. thepressure of such circuit,these two windings being cumulativelywound; a re- Avsistance'that ishigh compared with thev first aforesaid winding; and a switch having acontact actuated by the magnet and serially,

in the controlled circuit anormal follow-up contact engagingl the firstcontact and by "Whichffo'lloweu contact the second winding is included sunt of the generator, and an alternate contactfserially in thecontrolled circuit and engaged by the irs't'contact be` forethe firstcontact leaves its normal follow-up 'contactythe first two contactshavingl circuitA association' causing Ithem, by ytheir engagement, toshunt the resistance from the windings and by their-separation to bringthe second winding in shunt of the generator by way ofthe resistance,whilethe'latterl twocontacts', by their engagement, serve to establishthe controlled circuit.A s v I 4. :Ari electric 'current controllingdevice andjfaiiA electric circuit `controlled thereby, whieh circuit hasa current supplying genen A ator, device-including an electro-magnetharing .fm-energizing .Current .Wmdmg r.-

. iagsiteipg Camuiativeiy wanna, arida third `e'urreiit .from'uthe l.(zontrolled circuit, anenergizing pressure winding subiect totliepressiire-of "such circuit, these two windeneifgfiz'in y winding ofhiglhresi'stance coinlparedvt'it l.the first energizing/'winding anddifferentially wound Lwith. respect to the aforesid windings; and a'switch operablev by the electro-magnet an'dserving, when' unactuated bythe magnet, to open the controlled circuit and exclude the thirdwinding' from circuit relation with the first twowindings and whenactuated by the magnet -to close the controlled circuitand bring thethird winding in shunt of the generator by way of the second winding.

'5. An electric current controlling device and anA electric circuitcontrolled thereby, which circuit has a current supplying generator,said device includingan electro-inagiiet having an energizing currentwinding receivingcurrent fromvthe controlled circuit,

an energizing pressure winding subject to 8U .the pressure of suchcircuit, these two windv ingsbeing cumulatively wound, and a thirdenergizing winding differentially wound with respect to the aforesaidwindings; and

a switch operable by the electro-inagnet and serving, when unactuated bythe magnet, to open the controlled circuit and exclude the' thirdwinding from circuit relation with the first two windings and whenactuated by the magnet to close the controlled circuit and bring thethird winding in shunt of the generator byway of the second winding.

6. An electriccurrent controlling device and an electric circuitcontrolled thereby, which circuit has a current supplying gencrater,said device including an electro-magnet having a swinging armaturebridging the gap between two spaced apart portions .of the magneticcircuit of the magnet and swingingly mounted between its ends at one iof said magnetic circuit portions to"4 form therewith-'shunt relatedflux paths each serially relatedwith the fiux path furnished by theother magnetic circuit portion and the remaining portion of t-hearmature, a current winding supplied with current from said currentsupplying generator, and, a pressure winding receiving pressure fromsaid current supplying generator, and a switch operable bythe armatureof the elecat'or, said device including an electrogrnagnet having anenergizing current winding receiving current from the controlledcircuit', an energizing pressure winding subiect to the pressure of suchcircuit, these two wind-A ingsbeingcumulatively wound, and a thirdenergizing winding of' high'resistance comy paredwit i the firstenergizing winding and differentially wound with respect toV theaforesaid windings; and a switch having a contact yactuated by themagnet and serially inthe controlled circuit, a normal followu'p contactengaging the vfirst contact and by` which follow-up contact the secondwinding is includedin shunt of the generator, and an alternate contactserially in the controlled circuit `and engaged by the rstcontact beforethe first contact leaves its normal follow-up contact, the first twolcontacts having circuit association causing them, by their engagement,to shunt the third winding from the remaining windings and by theirseparation to bring the third winding inshunt of the generator, Whilethe latter two contacts, by their'engagement, serve to establish thecontrolled circuit.

8. An elec-tric current controlling device and an electric circuitcontrolled thereby, which circuit has a current supplying generator,said device including an electro-magnet having an energizing currentwinding receiving current from the controlled circuit, anV energizingpressure winding 4subject to the pressure of such circuit, these twowindings being cumulatively wound, and a third energizing windingdi'erentially wound with respect to the aforesaid windings; and a switchhaving a contact actuated by, the magnet and serially in the controlledcircuit, a normal follow-up contact engaging the first contact and bywhich follow-up contact the second winding is included in shunt of thegenerator, and an alternate contact serially in the controlled circuitand engaged by the first contactl before thefirst contact leaves itsnormal f ollowup contact, the first two contacts having circuitassociation caus ing them, by their engagement, to shunt the thirdwinding from the remaining windings and by their separation to bring thethird winding in shunt of the generator, while the latter two contacts,by vtheir engagement, serve to establish the controlled circuit.

9. 'An electric current controlling device and an electriccircuitcontrolled thereby,

which circuit has a current suplplying generator, said deviceincludingan e ectro-magnet having an'energizing current 'winding revceiving current from the controlled circuit, and a'n energizing pressurewinding subject to the pressure of such circuit, these two windingsbeing cumulatively wound; a resistance that is high compared with thefirst aforesaid winding; and a switch having a contact actuated by themagnet and serially in the controlled circuit, a normal follow-upcontact engaging the rst contact and by which follow-up contact thesecond winding is included in shunt of the generator, and an alternateContact,seriallyA in the controlled circuit and engagedvby the firstcontact before the first contact leaves its normal follow-up contact,the rsttwo-contacts having circuit association causing them, by theirengagement, to shunt the resistance from the windings and by theirseparation to include the resistance in series with the second wind-f.ing and in shunt ofthe generator, while thev latter two contacts, bytheir engagement,

serve to establish thecontrolled circuit.

nioaeao 10. An electric current controlling device and an electriccircuit controlled thereby, which circuit has a current supplyinggenerator, said device including an electro-magnet having an energizingcurrent winding receiving current from the controlled circuit,

an ener izinr ressure winding sub'ect to D 23 the pressure'of suchcircuit, thesetwo windings being cumulatively wound, and a thirdenergizing winding of high resistance compared with the first energizingwinding and differentiallywound with respect i' to the aforesaidwindings; and a switch operable by the electro-magnet and serving, whenunactuated by the magnet, to o en the controlled circuit and exclude thet ird winding from circuit relation with the rst two windings and whenactuated by the magnet-to close the controlled circuit and bring theihird winding in shunt of the generator.

1l. An electric current controlling device and an electric circuitcontrolled thereby, which circuit has a current supplying generator,said device including an electro-magnet having an energizing currentwinding receiving current from the controlled circuit, an yenergizingpressure winding subject to the pressure of such'circuit, these twowindings being cumulatively wound, and a third energizing windingdi'erentially wound with respect to the aforesaid windings; and a switchoperable by the electro"- magnet andserving, when unactuated by themagnet, to open the controlled circuit and exclude the third windingfrom circuit relation with the rst two windings and when actuated by themagnet to close the controlled circuit and bring the third winding` icssaid current supplying generator; and laV switch operable bythe armatureof the. electro-magnet and` in' controlling relation to said circuit.

t 13. An electric current controlling device and an' electric circuitcontrolled thereby,

which circuit -has`-a current supplying generator, said device includingan electro-'magnet having an energizing current winding receivingcurrent from the controlled circuit, and an energizing pressure windingsubject to the pressure of such circuit, these two /windings beingcumulatively wound; a re-- sistance that is high compared with the firstaforesaid winding; and a switch vhaving a contact actuated by the magnetand serially in the controlled circuit, a normal follow-up contactengaging the first contact and by which follow-up contact the secondWinding is included in shunt of the generator, and an alternate contactserially in the controlled circuit and engaged by the first contactbefore the first contact leaves its norma-l follow-up contact, thefirsttwo contacts having circuit association causing them,iby theirengagement, to shunt the resistance and by their separation to includethe resistance in series with the first Winding, While the latter twocontacts, by their engagement, serve to establish the controlledcircuit.

' 14. An electric current controlling device erator, said deviceincluding an electro-magnet having a swinging armature bridging the gapbetween two spaced apart portions of the magnetic swingingly mountedbetween its ends at one of said magnet-ic circuit portions to formtherewith shunt related fiuX paths each serially related with the fluxpath furnished by the other magnetic circuit portion and the remainingportion of the armature, and a current winding supplied with currentfrom said current supplying generator; and a switch operable by thearma-tur" of the electro-magnet and in controlling relation to saidcircuit.

In witness whereot I hereunto Vsubscribe my name.

ALBERT E. BERDON. Witnesses y A. J. VEBER,

E. C. BROMMER.

cijrcuit of the magnet and o

